The concept of the multistage combustion is for example disclosed in patent U.S Pat. No. 3,278,452 which describes a primary reforming reactor including a catalyst associated with a secondary reforming reactor, the latter receiving an additional supply of oxidant between catalytic beds arranged successively in the second reactor.
The main drawback of this type of reactors is that it requires a large amount of steam injected at the level of the oxidizer and/or of the fuel and whose production is often costly.
Furthermore, the drawback of steam excess is to modify the distribution between the hydrogen, the carbon dioxide and the carbon monoxide present in the synthetic gas.
French patent application EN.91/09,214 relates to the manufacturing of a synthetic gas of the type described above, according to which all of the operations are performed within a single housing; besides, in order notably to reduce steam consumption, the non catalytic combustion chamber is a short residence time chamber.
This realization requires a lower steam consumption.